diff --git a/.changelog/4505.txt b/.changelog/4505.txt
new file mode 100644
index 00000000000..5a3dcd00013
--- /dev/null
+++ b/.changelog/4505.txt
@@ -0,0 +1,3 @@
+```release-note:enhancement
+redis : marked `auth_string` on the `resource_redis_instance` resource as sensitive
+```
diff --git a/google/resource_redis_instance.go b/google/resource_redis_instance.go
index be65b8179b6..d78679a36a6 100644
--- a/google/resource_redis_instance.go
+++ b/google/resource_redis_instance.go
@@ -201,6 +201,7 @@ checked before each import/export operation.`,
 				Type:        schema.TypeString,
 				Description: "AUTH String set on the instance. This field will only be populated if auth_enabled is true.",
 				Computed:    true,
+				Sensitive:   true,
 			},
 			"project": {
 				Type:     schema.TypeString,
diff --git a/google/resource_redis_instance_test.go b/google/resource_redis_instance_test.go
index 9c4c79c5b60..0ebf698fcdd 100644
--- a/google/resource_redis_instance_test.go
+++ b/google/resource_redis_instance_test.go
@@ -143,8 +143,7 @@ resource "google_redis_instance" "test" {
     maxmemory-policy       = "noeviction"
     notify-keyspace-events = ""
   }
-  transit_encryption_mode = "SERVER_AUTHENTICATION"
-}
+  }
 `, name)
 }